5Medium
0/8

Sulfur trioxide, an essential intermediate in the manufacturing of sulfuric acid, is produced industrially via the Contact Process. The balanced symbol equation for this equilibrium reaction is:

2SO2(g)+O2(g)⇌2SO3(g)2\text{SO}_2(\text{g}) + \text{O}_2(\text{g}) \rightleftharpoons 2\text{SO}_3(\text{g})2SO2​(g)+O2​(g)⇌2SO3​(g)

a.

The reaction is carried out in a closed system.

State how you can tell from the equation that this reaction is reversible.

[1]
b.

What is meant by the term closed system?

[1]
c.

When dynamic equilibrium is reached, which of these statements are correct?

Select two correct statements:

  • The rate of the forward reaction is equal to the rate of the reverse reaction.
  • The forward and reverse reactions have completely stopped.
  • The concentrations of reactants and products remain constant.
  • The reaction vessel contains only sulfur trioxide.
  • The rate of the forward reaction is greater than the rate of the reverse reaction.
[2]
d.

The equilibrium position can be altered by changing the reaction temperature. Suggest one other change that could be made to the reaction conditions to alter the equilibrium position.

[1]
e.

A chemical plant predicts they will produce 1250 tonnes of sulfur trioxide. They actually produce 925 tonnes of sulfur trioxide. Calculate the percentage yield of sulfur trioxide.

[2]
f.

State why this reaction has an atom economy of 100%. Use the balanced symbol equation.

[1]

Equilibria Questions

Practise OCR GCSE Chemistry Equilibria with exam-style questions for Foundation and Higher tier. 35 questions, matched to the OCR GCSE Chemistry (J248) specification and written in Paper 1 and Paper 2 (Foundation Tier) or Paper 3 and Paper 4 (Higher Tier) style. Every question includes a full worked solution and mark scheme, so you can see where marks are awarded rather than just whether you got the answer right.

PreviousNext

Equilibria Questions

  1. GCSE
  2. /Chemistry
  3. /Equilibria